Deep packet scan hacker identification

ABSTRACT

Securing an accessible computer system typically includes receiving a data packet that includes a payload portion and an attribute portion, where the data packet is communicated between at least one access requestor and at least one access provider. At least the payload portion of the received data packet typically is monitored, where monitoring includes scanning the payload portion for at least one predetermined pattern. When the payload portion is determined to include at least one predetermined pattern, access by the access requestor to the access provider may be controlled. Monitoring the data packet may include scanning the payload portion while handling the data packet with a switch. Controlling access may include denying access by the access requestor to the access provider.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No.09/666,140, filed Sep. 20, 2000, and titled “Securing an AccessibleComputer System,” U.S. Provisional Application No. 60/227,309, filedAug. 24, 2000, and titled “Securing An Accessible Computer System,” andU.S. Provisional Application No. 60/278,422, filed Mar. 26, 2001, andtitled “Deep Packet Scan Hacker Identification,” each of which isincorporated by reference.

TECHNICAL FIELD

This invention relates to securing an accessible computer system.

BACKGROUND

Accessible computer systems have proven susceptible to various attacksby computer hackers. In one type of computer attack, a hacker attemptsto gain unauthorized access to an online computer service. In this typeof attack, the hacker may attempt to crack the password associated withthe known logon identification. The hacker may use a computer programthat associates passwords with the logon identification in rapidsuccession. This type of attack may allow the hacker to gainunauthorized access to a particular user's personal account on theonline computer service. The hacker also may attempt to use theunauthorized access to sabotage the online computer service. Whensubject to such attacks, accessible computer systems may be forced tocease operation.

SUMMARY

In one general aspect, securing an accessible computer system typicallyincludes receiving a data packet that includes a payload portion and anattribute portion, where the data packet is communicated between atleast one access requestor and at least one access provider. At leastthe payload portion of the received data packet typically is monitored,where monitoring the data packet includes scanning the payload portionfor at least one predetermined pattern. When the payload portion isdetermined to include at least one predetermined pattern, access by theaccess requestor to the access provider may be controlled.

Implementations may include one or more of the following features. Forexample, receiving a data packet may include receiving more than onedata packet and monitoring the data packets may include counting thenumber of data packets having payload portions that include thepredetermined pattern. Monitoring the data packet may include scanningthe payload portion while handling the data packet with a switch.

When more than one data packet is received, monitoring the data packetsmay include monitoring only the data packets that may be distinguished.When more than one data packet is received, securing the accessiblecomputer system further may include distinguishing from among the datapackets received at least one of the data packets for additionalprocessing, where monitoring the data packets includes monitoring thepayload portion of at least the one distinguished data packet. A datapacket may be distinguished based on an Internet address associated withthe data packet. Additionally or alternatively, when more than one datapacket is received, all of the received data packets may be monitored.

The access requestor may include a client and the access provider mayinclude a host. Data packets may be monitored when they are communicatedfrom the client to the host and/or when they are communicated from thehost to the client. The predetermined pattern may include a loginfailure message communicated from the host to the client. Data packetsmay include token-based protocol packets, TCP packets, and/or PPPpackets.

Access by the access requestor to the access provider may be controlledby denying access by the access requestor to the access provider. Accessalso may be controlled by rerouting the access requestor and/or byaffecting the bandwidth for communications between the access requestorand the access provider.

When more than one data packet is received, the access requestor may bedenied access to the access provider when a number of payload portionsthat include the predetermined pattern exceed a configurable thresholdnumber. Additionally or alternatively, the access requestor may bedenied access to the access provider when a number of payload portionsthat include the predetermined pattern exceed a configurable thresholdnumber during a configurable period of time.

These general and specific aspects may be implemented using a system, amethod, or a computer program, or any combination of systems, methods,and computer programs. Other features and advantages will be apparentfrom the description and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram that illustrates a physical level of anaccessible computer system.

FIG. 2 is a block diagram that illustrates a logical level of theaccessible computer system of FIG. 1.

FIG. 3 is a block diagram that illustrates components included in aswitch, such as those shown by FIGS. 1 and 2.

FIG. 4 is a block diagram that illustrates components included in amonitoring component of the switch of FIG. 3.

FIG. 5 is a block diagram that illustrates components included in anaccess controlling component of the switch of FIG. 3.

FIG. 6 is a flow chart illustrating a process for securing an accessiblecomputer system, which may be performed by the systems shown by FIGS.1-5.

FIG. 7 is a flow chart illustrating a process for monitoring thecomputer system for data packets as part of the process of FIG. 6.

FIG. 8 is a flow chart illustrating a process for controlling access toaccess providers as part of the process of FIG. 6.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

FIG. 1 is a block diagram that illustrates the physical level of anaccessible computer system 100. FIG. 1 shows access requestors 110connected through communication links 120 to an access network 130 thatis connected through communication links 140 to routers 150. The routers150 are connected through communication links 160 to switches 170 thatare connected through communication links 180 to access providers 190.

An access requestor 110 may include a client, and may be embodied in ageneral-purpose computer (e.g., a personal computer), a special-purposecomputer, a workstation, a server, a personal digital assistant, anelectronic organizer, a mobile phone, a pager, a device, a component, orother physical or virtual equipment or some combination of theseelements, any of which may be programmed or configured to respond to andexecute instructions in a defined manner.

The Internet is an example of an access network 130 that may be used toenable communications to/from access requestors 110. Other examples ofan access network 130 may include the World Wide Web, wide area networks(WANs), local area networks (LANs), analog or digital wired and wirelesstelephone networks (e.g. Public Switched Telephone Network (PSTN),Integrated Services Digital Network (ISDN), and Digital Subscriber Lines(xDSL)), radio, television, cable, satellite, and/or any other deliverymechanism for carrying data. The access network 130 generally isconnected to one or more routers 150 by communication links 140.

Each router 150 generally includes a computer processor, computersoftware, a hardware device, other physical or virtual equipment or somecombination of these elements that is capable of receiving, processingand transmitting information. In general, each router 150 routescommunications between one or more access requestors 110 and one or moreaccess providers 190. Communications received from an access provider190 generally are routed to an access requestor 110 through the accessnetwork 130. Communications received from an access requestor 110generally are routed to an access provider 190 through switch 170. Morespecifically, each router 150 receives a data packet and/or data requestfrom access requestor 110 and routes the data packet and/or data requestto one or more of the access providers 190 based on predefined criteriaor algorithms. The routers 150 are connected to one or more switches 170by communication links 160.

Switch 170 may include one or more hardware components and/or one ormore software components. It is capable of receiving one or more unitsof data and of transmitting the received data to one or more accessproviders 190 or routers 150 based on predefined criteria or algorithms.Switch 170 may perform load balancing algorithms such as hashingtechniques to avoid overwhelming any particular router 150 or accessprovider 190. Switch 170 also may perform the functions of the router150 as a separate or integrated component or device. Additionally oralternatively, switch 170 may include one or more processors and one ormore storage and memory devices, such as internal memory.

In some implementations, a switch 170 is structured and arranged toperform filtering and forwarding between different domains at the samelevel of the protocol stack in the OSI (“Open System Interconnection”)reference model. For example, in some networks, switch 170 may forwardEthernet frames between different Ethernet segments. In another example,switch 170 may forward IP packets between different IP subnets.

Switch 170 may include a device that performs network operations andfunctions in hardware (e.g., a chip or part of a chip). In someimplementations, the device may include an ASIC (“Application SpecificIntegrated Circuit”) implementing network operations logic directly on achip (e.g., logical gates fabricated on a silicon wafer and manufacturedinto a chip). For example, an ASIC chip may perform filtering byreceiving a packet, examining the IP address of the received packet, andfiltering based on the IP address by implementing a logical gatestructure in silicon.

Implementations of the device included in the switch 170 may includeusing a Field Programmable Gate Array (FPGA). A FPGA generally isdefined as including a chip or chips fabricated to allow third partydesigners to implement a variety of logical designs (e.g., group ofgates) on the chip. For example, a third party designer may load adesign within a FPGA to replace the received IP addresses with differentIP addresses, or may load a design within the FPGA to segment andreassemble IP packets as they are modified while being transmittedthrough different networks.

Implementations of the switch 170 may include a network processor. Anetwork processor generally is defined to include a chip or chips forallowing software to specify which network operations will be performed.A network processor may perform a variety of operations. One example ofa network processor may include several interconnected RISC (“ReducedInstruction Set Computer”) processors fabricated in a network processorchip. The network processor chip may implement software on some of theRISC processors that change an IP address of an IP packet. Other RISCprocessors in the network processor may implement software thatmaintains which terminals are receiving an IP stream. The switch 170 isconnected to multiple access providers 190 by communication links 180.

An access provider 190 may include software or hardware componentscapable of providing access by an access requestor 110 to desiredinformation or services. For instance, an access provider 190 mayinclude a host (e.g., an Internet Service Provider (ISP)), and it may beimplemented in a general-purpose computer (e.g., a personal computer) ora special-purpose computer capable of communicating with one or moreaccess requestors 110 by responding to and executing instructions in adefined manner. Other examples of an access provider 190 include aspecial-purpose computer, a work station, a server, a device, acomponent, other physical or virtual equipment or some combination ofthese elements that is capable of responding to and executinginstructions as described.

Communication links 120, 140, 160 and 180 may include, for example, awired communication pathway, such as a cable connection, or a wirelesscommunication pathway, such as a satellite link.

FIG. 2 is a block diagram that illustrates a logical level of a systemsuch as the system 100 illustrated in FIG. 1. FIG. 2 shows accessrequestors 110 connected to a switch 170 that is connected to accessproviders 190. In this figure, switch 170 may be representative of oneor more of access network 130, router 150 and switches 170, or acombination of these such as the combination described with respect toFIG. 1.

An access requestor 110 generally is used to establish a physical ornon-physical electronic connection with an access provider 190.Connections may be established on various levels using variousprotocols. For instance, a connection may be established on Level III(e.g., a packet based level), on Level IV (e.g., a protocol data unitbased level with flow control and error correction) or on some otherlevel (e.g., Level II) using an appropriate protocol capable ofestablishing a connection between an access requestor 110 and an accessprovider 190. More specifically, examples of protocols includeTransmission Control Protocol (TCP), Internet Protocol (IP), TCP/IP,User Datagram Protocol (UDP), UDP/IP, Layer Two Tunneling Protocol(L2TP), Point-to-Point Protocol (PPP), and a token-based protocol.

Access protocols are observed to establish a connection. For example, anaccess requestor 110 may send an access request through switch 170. Whenone of the access providers 190 receives the request, it responds to theaccess request by sending an acknowledgement that is routed back to theaccess requestor 110 through switch 170. When the access requestor 110receives the acknowledgement sent by the access provider 190, the accessrequestor 110 generates an acknowledgement that is sent back to theaccess provider 190 through switch 170. The completion of thistransaction establishes a connection between the access requestor 110and the access provider 190.

For purposes of this detailed description, the term connectiontransaction is used to describe one or more of sending, receiving, orexchanging the units of data necessary to use a protocol (e.g., TCP, IP,UDP, TCP/IP, UDP/IP, L2TP, PPP, and token-based) to establish acommunications link (e.g., wired, wireless, cable, and satellite)between the access requestor 110 and the access provider 190. Oneexample of a connection transaction results in a TCP connection betweenthe access requestor 110 and the access provider 190, where proceduresto establish a connection transaction use the synchronize (SYN) controlflag and involve an exchange of three messages. In this example, anaccess requestor 110 sends an access request (SYN REQ) to an accessprovider 190 through switch 170. The access provider 190 responds to theaccess requestor 110 through switch 170 with an acknowledgement (SYNACK). Then, the access requestor 110 sends an acknowledgement (ACK) tothe access provider 190 through switch 170. Other connectiontransactions also are possible between access requestor 110 and accessprovider 190 through switch 170 and can result in different types ofconnections (e.g., IP, TCP/IP, UDP, UDP/IP, L2TP, PPP, and token-based).

Deep packet scanning may be performed by a switch-based applicationdesigned to assist in areas of hacker prevention. In general, theapplication typically executes a deep packet scan (e.g., parsing payloadfrom packet header) on particular data passing through the switch 170(e.g., an L2 switch). The application may look for predeterminedpatterns (e.g., defined “tokens”) within at least the payload portion toidentify hackers trying to penetrate host system security.

FIG. 3 shows one example of the logical components of a switch designedto perform deep packet scanning, such as switch 170. As shown, switch170 may include the components necessary to perform a deep packet scanand to control access to access providers 190 by hackers. In particular,switch 170 may include a receiving component 310, a monitoring component320, and an access controlling component 330. These components generallyinclude one or more components embedded in software modules within acomputing device, but may be embedded in physical devices connected toone another or may be embedded in some combination of software modulesand physical devices. In other implementations, the componentsillustrated in FIG. 3 may be resident on an access provider 190.

The receiving component 310 typically is structured and arranged toreceive one or more data packets that each include a payload portionand/or an attribute portion. Each data packet typically is communicatedbetween at least one access requestor 110 and at least one accessprovider 190. The data packet may include any unit of data that iscommunicated between an access requestor 110 and an access provider 190using any type of protocol. For example, a data packet may include adatagram, such as the unit of data communicated using UDP, and/or atoken-based protocol packet. The payload portion may include the portionof the data packet that includes the main content of the data packetthat is communicated. The attribute portion may include, for example,information identifying the particular data packet, control information,address information (e.g., source IP address and destination IPaddress), and/or information such as that included in a header.

The monitoring component 320 typically is structured and arranged tomonitor at least the payload portion of the data packet received by thereceiving component 310. In addition to the payload portion, themonitoring component 320 also may be structured and arranged to monitorthe payload portion and/or the attribute portion of the data packet.More specific details regarding the receiving component 310 andmonitoring component 320 are provided below with respect to FIGS. 4 and5, respectively.

The access controlling component 330 is structured and arranged tocontrol access by the access requestor 110 to the access provider 190when one or a threshold number of data packets directed from the accessrequestor 110 to the access provider 190 are classified as suspect,e.g., as having payload portions that are determined to include one ormore predetermined patterns. For example, access may be controlled bydenying access by the access requestor 110 to the access provider 190,rerouting the access requestor 110, and/or affecting the bandwidth forcommunications between access requestor 110 and the access provider 190.

Referring to FIG. 4, the monitoring component 320 may include a scanningcomponent 410, a counting component 420, and a classifying component430. The scanning component 410 typically is structured and arranged toscan the payload portion of the data packet for one or morepredetermined patterns.

The scanning component 410 may scan the payload portions in numerousways. For example, the scanning component 410 may scan the payloadportion of every data packet communicated between the access requestor110 and access provider 190 for one of the predetermined patterns,including data packets communicated from the access requestor 110 to theaccess provider 190 and data packets communicated from the accessprovider 190 to the access requestor 110. Additionally or alternatively,the scanning component 410 may scan the payload portion of selected datapackets being communicated between the access requestor 110 and accessprovider 190. For example, the scanning component 410 may scan only thepayload portions communicated from the access provider 190 to the accessrequestor 110, it may scan only the payload portions communicated fromthe access requestor 110 to the access provider 190, or it may scan thepayload portions of less than all data packets communicated in one orboth directions between the access requestor 110 and the access provider190 based on some selection criteria (e.g., data packets havingattribute portions with certain characteristics, or data packetscommunicated during specified times or from specified origins). That is,the scanning component 410 may scan the payload portion of selected datapackets that are received by the receiving component 310, includingselected data packets communicated from the access requestor 110 to theaccess provider 190 and/or selected data packets communicated from theaccess provider 190 to the access requestor 110. Furthermore, thescanning component 410 may scan the payload portions using anycombination of the above scanning patterns.

The scanning component 410 typically scans the payload portion of a datapacket for at least one predetermined pattern. The predetermined patternmay be included in a payload portion communicated from the accessrequestor 110 to the access provider 190 and/or from the access provider190 to the access requestor 110. In one implementation, thepredetermined pattern may include the binary or hexadecimal equivalentof a login failure message that is communicated from the access provider190 to the access requestor 110. In another implementation, thepredetermined pattern may include the binary or hexadecimal equivalentof a login request message that is communicated from the accessrequestor 110 to the access provider 190.

For example, in one implementation, payload portions are scanned forlogin failure messages. The access requestor 110 typically sends a datapacket to an access provider 190 that includes a payload portion having,a login request and an attribute portion having the source IP addressfor the access requestor 110. The data packet and its embedded loginrequest typically pass through switch 170, where they ordinarily arereceived by receiving component 310, scanned by the scanning component410, and delivered to access provider 190. Typically, the accessprovider 190 responds to the login request data packet with one or moredata packets that may indicate whether the login request has resulted orwill result in a successful login. The payload portion of the datapackets communicated by the access provider 190 in response to the loginrequest data packet generally includes a payload portion with loginsuccess or login failure information and an attribute portion with theIP address of the access requestor 110 that sent the login request.Thus, when the login request does not or will not result in a successfullogin, the access provider 190 typically generates and sends one or moredata packets to the access requestor 110 that may include login failureinformation. The login failure information may include the binary,hexadecimal, numeric, or alphanumeric equivalent of one or more loginfailure reasons, for example, an incorrect login name or an incorrectpassword. The login failure message may be identified by any one ofseveral predetermined patterns. In one implementation, the login failuremessage includes a pattern that may be a sixteen byte signature locatedat a specific offset from the end of one of the data packetscommunicated from the access provider 190 to the access requestor 110.Other types of predetermined patterns also are possible, includingpatterns using, for example, varying the number of bytes, the protocol,the offset, or the location in a data packet. The scanning component 410may be programmed to scan the payload portion of the data packet for anyor all of these predetermined patterns.

Furthermore, the predetermined pattern may be established based on thedetected occurrence of data patterns among received access requests orother communications between access requestor 110 and access provider190, or between a group (physical or logical) of access requestors 110and access providers 190. For example, a repetitive sequence of datareflecting access requests submitted by a single access requestor 110 orseveral access requestors 110 to one or more access providers 190 may beused to define a predetermined pattern for contemporaneous or futurescanning.

In one implementation, the scanning component 410 may scan aconfigurable number of data packets for a predetermined patternassociated with a particular access requestor 110. For example, thepredetermined patterns may be included in any of several packetscommunicated from the access provider 190 to the access requestor 110following the data packet that included the login request communicatedfrom the access requestor 110 to the access provider 190. When the datapacket that includes the login request is received by receivingcomponent 310, the scanning component 410 may use information from theattribute portion of that data packet to identify the source of the datapacket. For instance, the scanning component 410 may use the source IPaddress information included in the attribute portion of that datapacket to identify the source of the data packet. The source IP addressmay be copied and stored in a table of IP addresses kept for all of thelogin requests received by receiving component 310. Then, the payloadportions of data packets that include the IP address in the attributeportion may be scanned. The scanning component 410 may scan aconfigurable number of payload portions within data packets associatedwith a tabled IP address. When the configurable number of payloadportions have been scanned without revealing one or a threshold numberor ratio of packets including the predetermined pattern, then the IPaddress may be removed from the table such that scanning of data packetsis no longer performed as a function of their association with the nowuntabled IP address. In another implementation, a similar methodologymay be employed to enable scanning of messages cumulatively receivedfrom several different access requestors 110.

The counting component 420 may be structured and arranged to performvarious different counting functions. For example, the countingcomponent 420 typically is structured and arranged to count a number ofpayload portions that are received by receiving component 310. Thus, thecounting component 420 may count the number of payload portions receivedby the receiving component 310 and that are associated with IP addressesthat have been tabled so that it may be determined when the configurablenumber of payload portions for the identified IP address has beenreached. Additionally or alternatively, the counting component 420 maybe structured and arranged to count the number of payload portions ofdata packets that include a predetermined pattern. For instance, if morethan a predetermined number of suspect messages are determined to havebeen received from the access requestor 110 or the group of accessrequestors 110, further suspect messages from the one or more accessrequestors 110 may be blocked or otherwise filtered or controlled by theaccess controlling component 330.

The classifying component 430 may be structured and arranged todetermine whether an access requestor 110 is “suspicious.” Theclassifying component 430 may determine whether an access requestor 110is suspicious based on information from the counting component 420. Forexample, when the counting component 420 counts a number of payloadportions that include a predetermined pattern from a particular accessrequestor 110 or a particular group of access requestors 110 that meetsor exceeds a configurable threshold number, then the classifyingcomponent 430 may classify that access requestor 110 or group of accessrequestors 110 as suspicious. A suspicious access requestor 110 or thesource IP address of the suspicious access requestor 110 may bemonitored by monitoring component 320 by having its IP address placed onan exception list such that access is controlled (e.g., denied) to theaccess providers 190. Conversely, a list may be provided to identifyaccess requestors 110 that have been identified as secure and/or trustedand for which monitoring is deemed unnecessary, or a combination ofthese lists may be used.

Referring to FIG. 5, the access controlling component 330 typicallyincludes an access preventer 510, a timer component 520, and a resetcomponent 530. The access preventer 510 typically is structured andarranged to control access to an access provider 190 by an accessrequestor 110 that has been classified as suspicious by monitoringcomponent 320. For example, in one implementation, when the classifyingcomponent 430 of monitoring component 320 classifies an access requestor110 as suspicious, the access preventer 510 may deny access by thesuspicious access requestor 110 forevermore, or for a configurableperiod of time. Similarly, when a group of access requestors 110 areclassified by the classifying component 430 as suspicious, the accesspreventer 510 may deny access by the entire group of access requestors110.

The access preventer 510 may effect this denial of access by asuspicious access requestor 110 by holding down the IP addressassociated with the particular access requestor 110 in the table of IPaddresses. For instance, the access preventer 510 may include or accessan exception list (e.g., access or exclusion list) that identifies alist of IP addresses corresponding to suspicious access requestors forwhich access will be permitted or denied. In one example, the scanningcomponent 410 may identify a payload portion as corresponding to aspecific access requestor 110 associated with an IP address. Beforedenying access by an access requestor 110 having a specific IP address,the access preventer 510 may first check the exception list anddetermine whether the access requestor 110 or its IP address isidentified as suspicious and therefore listed on the exception list. Inthis implementation, if the access requestor 110 or its IP address isnot on the exception list, then the access preventer 510 will allow thataccess requestor 110 access to the access provider 190.

In another implementation, the access preventer 510 may control accessby rerouting the access requestor 110. Additionally or alternatively,the access preventer 510 may control access by affecting the bandwidthfor communications between the access requestor 110 and the accessprovider 190 (e.g., by decreasing the available bandwidth).

In another implementation, a list of IP address may be maintained foraccess requestors 110 that may be permitted access to the accessproviders 190 notwithstanding a classification as suspicious. Thus,before denying access to a suspicious access requestor, or perhaps evenbefore or during classification by monitoring component 320, this listmay be checked to determine whether the IP address for an accessrequestor is eligible for access. For instance, in the case where asingle IP address may be used by multiple access requestors 110communicating with access providers 190 through a network addresstranslator (NAT) device, this IP address may be included on the list ofIP address that may be permitted access even if classified as suspiciousto avoid denying access to all of the access requestors communicatingthrough the NAT device based on suspicious activity by less than all ofthe access requestors 110.

Moreover, the access preventer 510 may deny access by a specific accessrequestor 110 based on a classification of that access requestor 110 assuspicious by the classifying component 430 when the scanning component410 and the counting component 420 identify a configurable number orratio of payload portions that include a predetermined pattern.

The timer component 520 may be structured and arranged to measurevarious configurable periods of time. For example, the timer component520 may be structured and arranged to measure the configurable period oftime during which the access preventer 510 denies access by the accessrequestor 110. In one implementation, the timer component 520 maymeasure the configurable period of time that an IP address from aparticular, e.g., suspicious, access requestor 110 is denied access.

Additionally or alternatively, the timer component 520 may be structuredand arranged to measure the configurable period of time during which aconfigurable number of payload portions including a predeterminedpattern are communicated through the switch 170. If a configurablenumber of payload portions including a predetermined pattern areidentified within the configurable period of time, then the accesspreventer 510 denies access by the access requestor 110.

Reset component 530 typically is structured and arranged to reset theconfigurable period of time measured by timer component 520 for which anaccess requestor 110 is denied access if the receiving component 320receives a new packet of data sent from such an access requestor 110.For example, if the access requestor 110 that is being denied accesssends a new login request during the configurable period of time that itis being denied access, reset component 530 will start a new time periodduring which the access requestor 110 will continue to be denied access.In this manner, traffic from a blocked access requestor 110 may continuebeing blocked until the access requestor 110 has refrained fromsubmitting an access request for at least a configurable period of time.

In addition to the above components and features typically included onswitch 170, the switch 170 may be programmed to include additionalfeatures. For instance, switch 170 may be programmed to include acurrent denied access table, which may include a source IP address, thetime period remaining for denying access, and a number of times aspecific IP address has been denied access. The switch 170 also may becapable of sending a message to a system monitor that includes theinformation included in the current denied access table. Additionally,the components included on switch 170 may be programmed by a user usinga Command Line Interface (CLI).

In one implementation, the components included on switch 170 may processin excess of fifty thousand data packets per second. In general, theswitch 170 typically can support a minimum of two Fiber Gigabit EthernetInterfaces (SC), and/or a minimum of twenty four Fast Ethernetinterfaces (RJ45).

FIG. 6 illustrates a process 600 for securing an accessible computersystem, which generally includes receiving a data packet (step 610),monitoring at least a payload portion of the data packet (step 620), andcontrolling access based on the payload contents (step 630). Thisprocess 600 typically is performed by a system such as the systemdescribed above with respect to FIGS. 1-5. For instance, process 600 maybe performed by a switch 170, by an access provider 190, or by acombination of the two. Process 600 also may be performed by any otherhardware device or software device capable of being programmed toreceive, process, and send instructions in the manner described.

More specifically, process 600 includes receiving a data packet thatincludes a payload portion and an attribute portion (step 610), wherethe data packet typically is communicated between at least one accessrequestor and at least one access provider. In this sense, receiving adata packet (step 610) also may include receiving multiple data packets,where each data packet includes a payload portion and/or an attributeportion. At least the payload portion of the data packet received ismonitored (step 620). Monitoring at least the payload portion of thedata packet (step 620) generally involves checking the payload portionfor a predetermined pattern of data, but also may include monitoring thepayload portion and/or the attribute portion of the data packet. Moredetails of one exemplary monitoring process are described with respectto FIG. 7. Based on whether the payload portion is determined to includeat least one predetermined pattern, access by the access requestor tothe access provider may be controlled (step 630), e.g., as describedwith respect to FIGS. 7 and 8.

Referring to FIG. 7, monitoring at least the payload portion of the datapacket (e.g., step 620 of FIG. 6) may include scanning the payloadportion for one or more predetermined patterns (step 710). Scanning thepayload portion (step 710) may be performed in numerous ways. Forexample, scanning the payload portion (step 710) may include scanningthe payload portion of every data packet communicated between the accessrequestor and access provider for one of the predetermined patterns,including data packets communicated from the access requestor to theaccess provider and data packets communicated from the access providerto the access requestor. Additionally or alternatively, scanning thepayload portion (step 710) may include scanning the payload portion ofselected data packets being communicated between the access requestorand access provider. For example, only the payload portions communicatedfrom the access provider to the access requestor may be scanned, or onlythe payload portions communicated from the access requestor to theaccess provider may be scanned, or the payload portions of less than alldata packets communicated in one or both directions between the accessrequestor and the access provider may be selected based on someselection criteria and scanned (e.g., data packets having attributeportions with certain characteristics, or data packets communicatedduring specified times or from specified origins). Furthermore, scanningthe payload portion (step 710) may include scanning the payload portionusing any combination of the above scanning methods.

Scanning the payload portion (step 710) typically includes scanning thepayload portion of a data packet for at least one predetermined pattern.Examples of predetermined patterns that may be included in the payloadportion are discussed above. In one example implementation, scanning thepayload portion (step 710) may include scanning the payload portion forlogin failure messages. In this case, a data packet typically isreceived (step 610) from an access requestor that includes a payloadportion having a login request and an attribute portion having thesource IP address for the access requestor. The data packet and itsembedded login request then are delivered to an access provider.Typically, the access provider responds to the login request data packetwith one or more data packets that may indicate whether the loginrequest has resulted or will result in a successful login. The payloadportion of the data packets communicated by the access provider inresponse to the login request data packet generally include a payloadportion with the login success or login failure information and anattribute portion with the IP address of the access requestor that sentthe login request. Thus, when a login request does not or will notresult in a successful login, the access provider typically generatesand sends one or more data packets to the access requestor that mayinclude login failure information, as discussed above. The data packetincluding the login failure information typically is received (step 610)and the payload portion is scanned for the login failure information(i.e., a predetermined pattern) (step 710).

Furthermore, the predetermined pattern may be established based on thedetected occurrence of data patterns among received access requests(step 610) or other communications between access requestor and accessprovider, or between a group (physical or logical) of access requestorsand access providers. For example, a repetitive sequence of datareflecting access requests submitted by a single access requestor orseveral access requestors to one or more access providers may be used todefine a predetermined pattern for contemporaneous or future scanning.

By scanning the payload portion (step 710) for a configurable number ofdata packets associated with a particular access requestor, it ispossible to count a number of payload portions which include thepredetermined pattern (step 720) and to determine whether the number ofpayload portions which include the predetermined pattern exceed aconfigurable threshold number (step 730), and thus to monitor thereceived data packets (step 620).

Counting a number of payload portions (step 720) may include performingvarious types of counts. For example, counting a number of payloadportions (step 720) may include counting the number of payload portionsreceived that are associated with IP addresses that have been tabled todetermine when the configurable number of payload portions for theidentified IP address has been reached. Additionally or alternatively,counting a number of payload portions (step 720) may include countingthe number of payload portions of data packets that include apredetermined pattern.

The number of payload portions counted generally are compared against athreshold to determine whether the source of the data packets issuspicious. Then, based on the determination made in step 730, accessmay be controlled in step 630. For instance, if the number of payloadportions which include the predetermined pattern is determined in step730 to meet or exceed the configurable threshold number, then the accessrequestor is denied access to the access provider (step 740). If thenumber of payload portions which include the predetermined pattern doesnot meet or exceed the configurable threshold number, then the accessrequestor is permitted access to the access provider (step 750).

More specifically, controlling access by the access requestor to theaccess provider (step 630) may include denying access by the accessrequestor forevermore, or for a configurable period of time (step 740).For example, in one implementation, when the scanning the payloadportion (step 710) identifies a predetermined pattern in a payloadportion of a data packet, access may be denied by the access requestorthat communicated the data packet to the access provider. In otherexample implementations, access may be denied by the access requestor tothe access provider only after a configurable number of payload portionsthat include a predetermined pattern have been counted or access may bedenied to an entire group of access requestors that have singularly orcollectively been identified as suspicious.

Controlling access (step 630) may be achieved by holding down an IPaddress associated with a specific access requestor in the table of IPaddresses. Additionally or alternatively, prior to denying access (step630) by an access requestor having a specific IP address, the IP addressmay be compared against an exception list (e.g., access or exclusionlist) to determine whether the IP address is included in the exceptionlist. If the IP address is on the exception list, then the accessrequestor will be allowed or denied access to the access provider, asappropriate.

Additionally or alternatively, controlling access (step 630) may includererouting the access requestor and/or affecting the bandwidth forcommunications between the access requestor and the access provider.

In the above implementation, specific data packets may be identified forscanning by using the IP address included in the attribute portion ofthe data packet. For instance, when the data packet including the loginrequest is received (step 610), the source IP address may be copied andstored temporarily in a table of IP addresses kept for all of the loginrequests that are received. Then, a configurable number of payloadportions within data packets having attribute portions that include anidentified and/or tabled IP address may be scanned (step 710), andsuspect data packets counted (step 720). When the configurable number ofpayload portions have been scanned without revealing one or a thresholdnumber or ratio of packets including the predetermined pattern (step730), then the IP address may be removed from the table such that accessby the access requester is permitted (step 740) and scanning of datapackets is no longer performed as a function of their association withthe now untabled IP address. In another implementation, a similarmethodology may be employed to enable scanning of messages cumulativelyreceived from several different access requestors.

Referring to FIG. 8, another implementation of controlling access (step630) is described. As shown, controlling access may include denyingaccess to a specific access requestor when a configurable number orratio of payload portions is determined to include a predeterminedpattern over a configurable period of time (step 810). If theconfigurable period of time has elapsed (step 815), then the accessrequestor is allowed to access the access provider (step 820). If theconfigurable period of time has not elapsed (step 815), then a query ismade as to whether a new request from the blocked access requestor hasbeen received (step 825). If a new login request has been received fromthe blocked access requestor during the configurable period of time(step 825), then the configurable period of time may be reset (step830). If a new login request has not been received from the blockedaccess requestor (step 825), then access is still denied for theremaining configurable period of time, but the configurable period oftime is not reset.

Additionally or alternatively, other components and processes may beused to identify suspicious access requestors and control access tothose access requestors. For example, activities may be monitoredfollowing a successful login of an access requestor to an accessprovider, such as, for example by monitoring user account login records.A back-end network component may monitor, for example, these useraccount login records for patterns of suspicious activity that may goundetected by the monitoring process on switch 170. For patterns ofsuspicious activity discovered by the back-end network component, theback-end network component may notify switch 170 to control access tothese particular access requestors (e.g., by denying them access).

The systems, methods and techniques described here may be implemented indigital electronic circuitry, computer hardware, firmware, software, orcombinations of these media. Implementations may include appropriateinput and output devices, a computer processor, and a computer programproduct tangibly embodied in a machine-readable storage device forexecution by a programmable processor. Implementations may include aprogrammable processor executing a program of instructions to performdesired functions by operating on input data and generating appropriateoutput. Implementations may include one or more computer programs thatare executable on a programmable system including at least oneprogrammable processor coupled to receive data and instructions from,and to transmit data and instructions to, a data storage system, atleast one input device, and at least one output device. Each computerprogram may be implemented in a high-level procedural or object-orientedprogramming language, or in assembly or machine language if desired; andin any case, the language may be a compiled or an interpreted language.Suitable processors include, by way of example, both general and specialpurpose microprocessors. Generally, a processor will receiveinstructions and data from a read-only memory and/or a random accessmemory. Storage devices suitable for tangibly embodying computer programinstructions and data include all forms of non-volatile memory,including by way of example semiconductor memory devices, such as EPROM,EEPROM, and flash memory devices; magnetic disks such as internal harddisks and removable disks; magneto-optical disks; and CD-ROM disks. Anyof the foregoing may be supplemented by, or incorporated in,specially-designed ASICs (application-specific integrated circuits).

A number of implementations have been described. Nevertheless, it willbe understood that various modifications may be made without departingfrom the spirit and scope of the claims. For example, advantageousresults still could be achieved if steps of the disclosed techniqueswere performed in a different order and/or if components in thedisclosed systems were combined in a different manner and/or replaced orsupplemented by other components. Accordingly, other implementations arewithin the scope of the following claims.

1. A method for securing an accessible computer system, the methodcomprising: receiving more than one data packet at a network device,each data packet including a payload portion and an attribute portionand being communicated between at least one access requestor and atleast one access provider through the network device; monitoring, at thenetwork device, at least the payload portion of the data packetsdirected from at least one of the access providers to at least one ofthe access requestors by scanning the payload portion for at least onepredetermined pattern and counting a number of data packets havingpayload portions that include the predetermined pattern; and using thenetwork device to deny communication of subsequent data packets from theaccess requestor to the access provider when a number of payloadportions of the data packets received from the access provider to theaccess requestor are deemed to include the predetermined pattern exceeda configurable threshold number.
 2. The method as in claim 1 whereinmonitoring the data packets includes scanning the payload portion whilehandling the data packets with a network device.
 3. The method as inclaim 2 wherein monitoring the data packet includes monitoring only atleast one data packet that is distinguished.
 4. The method as in claim 1wherein: securing the accessible computer system further comprisesdistinguishing at least one of the data packets from among the datapackets received for additional processing, and monitoring the payloadportion includes monitoring the payload portion of the at least one datapacket distinguished.
 5. The method as in claim 4 wherein the at leastone data packet is distinguished based on an Internet address associatedwith the data packet.
 6. The method as in claim 1 wherein monitoring thedata packet includes monitoring all of the data packets received.
 7. Themethod as in claim 1 wherein the predetermined pattern includes a loginfailure message communicated from the access provider to the accessrequestor.
 8. The method of claim 7 wherein the predetermined patternfurther includes a login request message.
 9. The method of claim 7wherein the login failure message includes a signature located at aspecific offset from an end of the data packet communicated from theaccess provider to the access requestor.
 10. The method of claim 7wherein the login failure message includes login failure reasons. 11.The method as in claim 1 wherein the data packets include a token-basedprotocol packet, or a TCP packet or a PPP packet.
 12. The method as inclaim 1 wherein denying communication of subsequent data packetsincludes affecting bandwidth for communications between the accessrequestor and the access provider.
 13. The method as in claim 1 furthercomprising rerouting the access requestor.
 14. The method as in claim 1wherein denying data packets from the access requestor to the accessprovider includes denying data packets from the access requestor to theaccess provider when a number of payload portions that include thepredetermined pattern exceed a configurable threshold number during aconfigurable period of time.
 15. The method as in claim 1 whereindenying communication of subsequent data packets from the accessrequestor to the access provider further comprises denying communicationof subsequent data packets from a group of access requestors to theaccess provider when a number of payload portions within the datapackets that are received, from the access provider by at least oneaccess requester which is a group member, include the predeterminedpattern exceed a configurable threshold number.
 16. The method of claim1 further comprises determining whether the access requestor is on apermitted access list that is associated with the access requestorsallowing subsequent access from the access requestor to the accessprovider conditioned on whether or not the access requestor isdetermined to be included in the permitted access list.
 17. The methodof claim 16 wherein determining whether the access requestor is includedin the permitted access list further comprises determining whether theIP address of the access requestor is included in the permitted accesslist.
 18. The method of claim 1 wherein subsequent data packets from theaccess requestor to the access provider is denied for a pre-determinedand limited period of time.
 19. The method of claim 18 wherein denial ofsubsequent data packets from by the access provider starts a newpre-determined and limited time period upon detecting an access requestthe access requestor during the elapsing of the predetermined andlimited period of time.
 20. The method of claim 1 wherein denyingsubsequent data packets from the access requestor is performed inresponse to a command received from the access provider, irrespective ofthe inspection of data packets received from the access provider. 21.The method of claim 1 wherein the network device is a physicallyindependent processor from the access providers.
 22. The method of claim1 wherein the network device is a switch.
 23. The method of claim 1wherein the access provider is a device configurable to make adetermination of whether access is permitted.
 24. The method of claim 23wherein the access provider is a field arbitrator, configured todetermine whether access is provided.
 25. A system that connects aplurality of access requestors to a plurality of access providers forsecuring an accessible computer system, comprising: a receivingcomponent that is structured and arranged to receive more than one datapacket, each data packet including a payload portion and an attributeportion and being communicated between at least one access requestor andat least one access provider; a monitoring component that is structuredand arranged to monitor at least the payload portion of the data packetsdirected from at least one of the access providers to at least one ofthe access requestors and includes a scanning component that isstructured and arranged to scan the payload portion for at least onepredetermined pattern and to count a number of data packets havingpayload portions that include the predetermined pattern; and an accesscontrolling component that is structured and arranged to denycommunication of subsequent data packets from the access requestor tothe access provider when a number of payload portions of data packetsreceived from the access provider to the access requestor that includethe predetermined pattern exceed a configurable threshold number. 26.The system of claim 25 wherein the monitoring component includes ascanning component that is structured and arranged to scan the payloadportion while handling the data packets with a network device.
 27. Thesystem of claim 26 wherein the monitoring component is structured andarranged to monitor only at least one data packet that is distinguished.28. The system of claim 25 wherein: the system further comprises adistinguishing component that is structured and arranged to distinguishat least one of the data packets from among the data packets receivedfor additional processing, and the monitoring component is structuredand arranged to monitor the payload portion of the at least one datapacket distinguished.
 29. The system of claim 28 wherein the at leastone data packet is distinguished based on an Internet address associatedwith the data packet.
 30. The system of claim 25 wherein the monitoringcomponent is structured and arranged to monitor all of the data packetsreceived.
 31. The system of claim 25 wherein the data packets aremonitored when communicated from the access requestor to the accessprovider.
 32. The system of claim 25 wherein the predetermined patternincludes a login failure message communicated from the access providerto the access requestor.
 33. The system of claim 25 wherein the datapackets include a token-based protocol packet, or a TCP packet or a PPPpacket.
 34. The system of claim 25 wherein the access controllingcomponent is structured and arranged to affect bandwidth forcommunications between the access requestor and the access provider. 35.The system of claim 25 wherein the access controlling component isstructured and arranged to reroute the access requestor.
 36. The systemof claim 25 wherein the access controlling component is structured andarranged to deny subsequent access by the access requestor to the accessprovider when a number of payload portions that include thepredetermined pattern exceed a configurable threshold number during aconfigurable period of time.
 37. A computer program stored on a networkdevice computer that connects a plurality of access requestors to aplurality of access providers for securing an accessible computersystem, comprising: a receiving code segment that causes the computer toreceive more than one data packet, each data packet including a payloadportion and an attribute portion and being communicated between at leastone access requestor and at least one access provider; a monitoring codesegment that causes the computer to monitor at least the payload portionof the data packets directed from at least one of the access providersto at least one of the access requestors and includes a scanning codesegment that causes the computer to scan the payload portion for atleast one predetermined pattern and to count a number of data packetshaving payload portions that include the predetermined pattern; and anaccess controlling code segment that causes the computer to denysubsequent communication of data packets from the access requestor tothe access provider when a number of payload portions of the datapackets received from the access provider to the access requestor thatinclude the predetermined pattern exceed a configurable thresholdnumber.
 38. The computer program of claim 37 wherein the monitoring codesegment includes a scanning code segment that causes the computer toscan the payload portion while handling the data packets with a networkdevice.
 39. The computer program of claim 38 wherein the monitoring codesegment causes the computer to monitor only at least one data packetthat is distinguished.
 40. The computer program of claim 37 wherein: thecomputer program further comprises a distinguishing code segment thatcauses the computer to distinguish at least one of the data packets fromamong the data packets received for additional processing, and themonitoring code segment causes the computer to monitor the payloadportion of the at least one data packet distinguished.
 41. The computerprogram of claim 40 wherein the at least one data packet isdistinguished based on an Internet address associated with the datapacket.
 42. The computer program of claim 37 wherein the monitoring codesegment causes the computer to monitor all of the data packets received.43. The computer program of claim 37 wherein the data packets aremonitored when communicated from the access requestor to the accessprovider.
 44. The computer program of claim 37 wherein the predeterminedpattern includes a login failure message communicated from the accessprovider to the access requestor.
 45. The computer program of claim 37wherein the data packets include a token-based protocol packet, or a TCPpacket or a PPP packet.
 46. The computer program of claim 37 wherein theaccess controlling code segment causes the computer to affect bandwidthfor communications between the access requestor and the access provider.47. The computer program of claim 37 wherein the access controlling codesegment causes the computer to reroute the access requestor.
 48. Thecomputer program of claim 37 wherein the access controlling code segmentcauses the computer to deny subsequent access by the access requestor tothe access provider when a number of payload portions that include thepredetermined pattern exceed a configurable threshold number during aconfigurable period of time.